#pragma once
#include "../server.hpp"
#include <fstream>
#include <sys/stat.h>
#include <regex>

#define DEFAULT_TIMEOUT 30

std::unordered_map<int, std::string> _status_msg = {
            {100, "Continue"},
            {101, "Switching Protocol"},
            {102, "Processing"},
            {103, "Early Hints"},
            {200, "OK"},
            {201, "Created"},
            {202, "Accepted"},
            {203, "Non-Authoritative Information"},
            {204, "No Content"},
            {205, "Reset Content"},
            {206, "Partial Content"},
            {207, "Multi-Status"},
            {208, "Already Reported"},
            {226, "IM Used"},
            {300, "Multiple Choice"},
            {301, "Moved Permanently"},
            {302, "Found"},
            {303, "See Other"},
            {304, "Not Modified"},
            {305, "Use Proxy"},
            {306, "unused"},
            {307, "Temporary Redirect"},
            {308, "Permanent Redirect"},
            {400, "Bad Request"},
            {401, "Unauthorized"},
            {402, "Payment Required"},
            {403, "Forbidden"},
            {404, "Not Found"},
            {405, "Method Not Allowed"},
            {406, "Not Acceptable"},
            {407, "Proxy Authentication Required"},
            {408, "Request Timeout"},
            {409, "Conflict"},
            {410, "Gone"},
            {411, "Length Required"},
            {412, "Precondition Failed"},
            {413, "Payload Too Large"},
            {414, "URI Too Long"},
            {415, "Unsupported Media Type"},
            {416, "Range Not Satisfiable"},
            {417, "Expectation Failed"},
            {418, "I'm a teapot"},
            {421, "Misdirected Request"},
            {422, "Unprocessable Entity"},
            {423, "Locked"},
            {424, "Failed Dependency"},
            {425, "Too Early"},
            {426, "Upgrade Required"},
            {428, "Precondition Required"},
            {429, "Too Many Requests"},
            {431, "Request Header Fields Too Large"},
            {451, "Unavailable For Legal Reasons"},
            {501, "Not Implemented"},
            {502, "Bad Gateway"},
            {503, "Service Unavailable"},
            {504, "Gateway Timeout"},
            {505, "HTTP Version Not Supported"},
            {506, "Variant Also Negotiates"},
            {507, "Insufficient Storage"},
            {508, "Loop Detected"},
            {510, "Not Extended"},
            {511, "Network Authentication Required"}
};

std::unordered_map<std::string, std::string> _mime_msg = {
            {".aac", "audio/aac"},
            {".abw", "application/x-abiword"},
            {".arc", "application/x-freearc"},
            {".avi", "video/x-msvideo"},
            {".azw", "application/vnd.amazon.ebook"},
            {".bin", "application/octet-stream"},
            {".bmp", "image/bmp"},
            {".bz", "application/x-bzip"},
            {".bz2", "application/x-bzip2"},
            {".csh", "application/x-csh"},
            {".css", "text/css"},
            {".csv", "text/csv"},
            {".doc", "application/msword"},
            {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
            {".eot", "application/vnd.ms-fontobject"},
            {".epub", "application/epub+zip"},
            {".gif", "image/gif"},
            {".htm", "text/html"},
            {".html", "text/html"},
            {".ico", "image/vnd.microsoft.icon"},
            {".ics", "text/calendar"},
            {".jar", "application/java-archive"},
            {".jpeg", "image/jpeg"},
            {".jpg", "image/jpeg"},
            {".js", "text/javascript"},
            {".json", "application/json"},
            {".jsonld", "application/ld+json"},
            {".mid", "audio/midi"},
            {".midi", "audio/x-midi"},
            {".mjs", "text/javascript"},
            {".mp3", "audio/mpeg"},
            {".mpeg", "video/mpeg"},
            {".mpkg", "application/vnd.apple.installer+xml"},
            {".odp", "application/vnd.oasis.opendocument.presentation"},
            {".ods", "application/vnd.oasis.opendocument.spreadsheet"},
            {".odt", "application/vnd.oasis.opendocument.text"},
            {".oga", "audio/ogg"},
            {".ogv", "video/ogg"},
            {".ogx", "application/ogg"},
            {".otf", "font/otf"},
            {".png", "image/png"},
            {".pdf", "application/pdf"},
            {".ppt", "application/vnd.ms-powerpoint"},
            {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
            {".rar", "application/x-rar-compressed"},
            {".rtf", "application/rtf"},
            {".sh", "application/x-sh"},
            {".svg", "image/svg+xml"},
            {".swf", "application/x-shockwave-flash"},
            {".tar", "application/x-tar"},
            {".tif", "image/tiff"},
            {".tiff", "image/tiff"},
            {".ttf", "font/ttf"},
            {".txt", "text/plain"},
            {".vsd", "application/vnd.visio"},
            {".wav", "audio/wav"},
            {".weba", "audio/webm"},
            {".webm", "video/webm"},
            {".webp", "image/webp"},
            {".woff", "font/woff"},
            {".woff2", "font/woff2"},
            {".xhtml", "application/xhtml+xml"},
            {".xls", "application/vnd.ms-excel"},
            {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
            {".xml", "application/xml"},
            {".xul", "application/vnd.mozilla.xul+xml"},
            {".zip", "application/zip"},
            {".3gp", "video/3gpp"},
            {".3g2", "video/3gpp2"},
            {".7z", "application/x-7z-compressed"}
};

class Util
{
public:
    // 字符串分割函数，将src按sep进行分割，得到各个子串放在arr中，返回子串的数量
    static size_t Split(const std::string &src, const std::string &sep, std::vector<std::string> *arr)
    {
        int offset = 0;
        while (offset < src.size())
        {
            size_t pos = src.find(sep, offset); // 在src偏移量offset处，开始向后查找sep字符子串，返回相应位置
            if (pos == std::string::npos)       // 没有找到特定的字符
            {
                if (pos == src.size())
                    break;
                arr->push_back(src.substr(offset)); // 将剩余部分放入子串中
                return arr->size();
            }
            if (pos == offset)
            {
                offset = pos + sep.size();
                continue;
            }
            arr->push_back(src.substr(offset, pos - offset));
            offset = pos + sep.size();
        }
        return arr->size();
    }
    // 读取文件所有内容
    static bool RealFile(const std::string &filename, std::string *buff)
    {
        std::ifstream ifs(filename, std::ios::binary);
        if (ifs.is_open() == false)
        {
            LOG(ERROR, "open %s file failed", filename.c_str());
            return false;
        }
        size_t fsize = 0;
        ifs.seekg(0, ifs.end);
        fsize = ifs.tellg();
        ifs.seekg(0, ifs.beg);
        buff->resize(fsize);
        ifs.read(&(*buff)[0], fsize);
        if (ifs.good() == false)
        {
            LOG(ERROR, "read %s file failed", filename.c_str());
            ifs.close();
            return false;
        }
        ifs.close();
        return true;
    }
    // 向文件中写入数据
    static bool WriteFile(const std::string &filename, const std::string &buff)
    {
        std::ofstream ofs(filename, std::ios::binary | std::ios::trunc);
        if (ofs.is_open() == false)
        {
            printf("open %s file failed", filename.c_str());
            return false;
        }
        ofs.write(buff.c_str(), buff.size());
        if (ofs.good() == false)
        {
            LOG(ERROR, "write %s file failed", filename.c_str());
            ofs.close();
            return false;
        }
        ofs.close();
        return true;
    }
    // URL编码，避免URL中资源路径与查询字符串中的特殊字符与http请求中特殊字符产生歧义
    // 编码格式：将特殊字符的ascii值，转换为两个16进制字符
    static std::string UrlEncode(const std::string &url, bool convert_space_to_plus)
    {
        std::string res;
        for (auto &c : url)
        {
            if (c == '.' || c == '-' || c == '_' || c == '~' || isalnum(c))
            {
                res += c;
                continue;
            }
            if (c == ' ' && convert_space_to_plus)
            {
                res += '+';
                continue;
            }
            // 剩下的字符都是需要编码成为 %HH 格式
            char tmp[4] = {0};
            snprintf(tmp, 4, "%%%02X", c);
            res += tmp;
        }
        return res;
    }

    static char Hextoi(char ch)
    {
        if (ch >= '0' && ch <= '9')
            return ch - '0';
        else if (ch >= 'a' && ch <= 'z')
            return ch - 'a' + 10;
        else if (ch >= 'A' && ch <= 'Z')
            return ch - 'A' + 10;
        return -1;
    }
    // URL解码
    static std::string UrlDecode(const std::string &url, bool convert_plus_to_space)
    {
        // 遇到了%，则将紧跟其后的两个字符，转换成数字，第一个数字左移4位，然后加上第二个数字
        std::string res;
        for (int i = 0; i < url.size(); ++i)
        {
            if (url[i] == '+' && convert_plus_to_space)
            {
                res += ' ';
                continue;
            }
            if (url[i] == '%' && i + 2 < url.size())
            {
                char v1 = Hextoi(url[i + 1]);
                char v2 = Hextoi(url[i + 2]);
                char v = (v1 << 4) + v2;
                i += 2;
                res += v;
                continue;
            }
            res += url[i];
        }
        return res;
    }
    // 响应状态码的描述信息获取
    static std::string StatusDesc(int statu)
    {
        auto it = _status_msg.find(statu);
        if (it != _status_msg.end())
            return it->second;
        return "Unknown";
    }
    // 根据文件后缀名获取文件mime
    static std::string ExtMime(const std::string &filename)
    {
        // 先获取文件扩展名，根据扩展名获取mime
        size_t pos = filename.find_last_of('.');
        if (pos == std::string::npos)
            return "application/octet-stream";
        std::string ext = filename.substr(pos);
        auto it = _mime_msg.find(ext);
        if (it == _mime_msg.end())
            return "application/octet-stream";
        return it->second;
    }
    // 判断一个文件是否是一个目录
    static bool IsDirectory(const std::string &filename)
    {
        struct stat st;
        int ret = stat(filename.c_str(), &st);
        if (ret < 0)
            return false;

        return S_ISDIR(st.st_mode);
    }
    // 判断一个文件是否是一个普通文件
    static bool IsRegular(std::string &filename)
    {
        struct stat st;
        int ret = stat(filename.c_str(), &st);
        if (ret < 0)
            return false;

        return S_ISREG(st.st_mode);
    }
    // http请求的资源路径有效性判断
    static bool VaildPath(const std::string &path)
    {
        std::vector<std::string> subdir;
        Split(path, "/", &subdir);
        int level = 0;
        for (const std::string &dir : subdir)
        {
            if (dir == "..")
            {
                level--;
                // 任意一层走出相对根目录，就认为有问题
                if (level < 0)
                    return false;
                continue;
            }
            level++;
        }
        return true;
    }
};

class HttpRequest
{
public:
    std::string _method;                                   // 请求方法
    std::string _path;                                     // 资源路径
    std::string _version;                                  // 协议版本
    std::string _body;                                     // 请求正文
    std::smatch _matches;                                  // 资源路径的正则提取数据
    std::unordered_map<std::string, std::string> _headers; // 头部字段
    std::unordered_map<std::string, std::string> _params;  // 查询字符串
public:
    HttpRequest() : _version("HTTP/1.1")
    {
    }
    void ReSet()
    {
        _method.clear();
        _path.clear();
        _version = "HTTP/1.1";
        _body.clear();
        std::smatch match;
        _matches.swap(match);
        _headers.clear();
        _params.clear();
    }
    // 插入头部字段
    void SetHeader(const std::string &key, const std::string &val)
    {
        _headers.insert(std::make_pair(key, val));
    }
    // 判断是否存在指定头部字段
    bool HasHeader(const std::string &key) const
    {
        auto it = _headers.find(key);
        if (it == _headers.end())
            return false;
        return true;
    }
    // 获取指定头部字段的值
    std::string GetHeader(const std::string &key) const
    {
        auto it = _headers.find(key);
        if (it == _headers.end())
            return "";
        return it->second;
    }
    // 插入查询字符串
    void SetParam(const std::string &key, const std::string &val)
    {
        _params.insert(std::make_pair(key, val));
    }
    // 判断是否有某个指定的查询字符串
    bool HasParam(const std::string &key) const
    {
        auto it = _params.find(key);
        if (it == _params.end())
            return false;
        return true;
    }
    // 获取指定的查询字符串
    std::string GetParam(const std::string &key) const
    {
        auto it = _params.find(key);
        if (it == _params.end())
            return "";
        return it->second;
    }
    // 获取正文长度
    size_t ContentLength() const
    {
        bool ret = HasHeader("Content-Length");
        if (ret == false)
            return 0;
        std::string clen = GetHeader("Content-Length");
        return std::stol(clen);
    }
    // 判断是否是短连接
    bool Close() const
    {
        // 没有Connection字段，或者有Connection但是值是close，则都是短连接，否则都是长连接
        if (HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive")
        {
            return false;
        }
        return true;
    }
};

class HttpResponse
{
public:
    int _statu;
    bool _redirect_flag;
    std::string _body;
    std::string _redirect_url;
    std::unordered_map<std::string, std::string> _headers;

public:
    HttpResponse() : _redirect_flag(false), _statu(200)
    {}
    HttpResponse(int statu) : _redirect_flag(false), _statu(statu)
    {
    }
    int Statu()
    {
        return _statu;
    }
    void ReSet()
    {
        _statu = 200;
        _redirect_flag = false;
        _body.clear();
        _redirect_url.clear();
        _headers.clear();
    }
    void SetHeader(const std::string &key, const std::string &val)
    {
        _headers.insert(std::make_pair(key, val));
    }
    bool HasHeader(const std::string &key)
    {
        auto it = _headers.find(key);
        if (it == _headers.end())
            return false;
        return true;
    }
    std::string GetHeader(const std::string &key)
    {
        auto it = _headers.find(key);
        if (it == _headers.end())
            return "";
        return it->second;
    }
    void SetContent(const std::string &body, const std::string &type = "text/html")
    {
        _body = body;
        SetHeader("Content-Type", type);
    }
    void SetRedirect(const std::string &url, int statu = 302)
    {
        _statu = statu;
        _redirect_flag = true;
        _redirect_url = url;
    }
    bool Close()
    {
        // 没有Connection字段，或者有Connection但是值是close，则都是短连接，否则都是长连接
        if (HasHeader("Connection") == true && GetHeader("Connection") == "keep-alive")
        {
            return false;
        }
        return true;
    }
};

typedef enum
{
    RECV_HTTP_ERROR,
    RECV_HTTP_LINE,
    RECV_HTTP_HEAD,
    RECV_HTTP_BODY,
    RECV_HTTP_OVER
} HttpRecvStatu;

#define MAX_LINE 8192
class HttpContext
{
private:
    int _resp_statu;           // 响应状态码
    HttpRecvStatu _recv_statu; // 当前接收及解析的阶段状态
    HttpRequest _request;      // 已经解析得到的请求信息
private:
    bool ParseHttpLine(const std::string &line)
    {
        std::smatch matches;
        std::regex e("(GET|HEAD|POST|PUT|DELETE) ([^?]*)(?:\\?(.*))? (HTTP/1\\.[01])(?:\n|\r\n)?", std::regex::icase);
        bool ret = std::regex_match(line, matches, e);
        if (ret == false)
        {
            _recv_statu = RECV_HTTP_ERROR;
            _resp_statu = 400; // bad request
            return false;
        }
        // 0 : GET /bitejiuyeke/login?user=xiaoming&pass=123123 HTTP/1.1
        // 1 : GET
        // 2 : /bitejiuyeke/login
        // 3 : user=xiaoming&pass=123123
        // 4 : HTTP/1.1
        // 请求方法的获取
        _request._method = matches[1];
        std::transform(_request._method.begin(), _request._method.end(), _request._method.begin(), ::toupper);
        // 资源路径的获取,需要进行URL解码操作,但是不需要+转空格
        _request._path = Util::UrlDecode(matches[2], false);
        // 协议版本的获取
        _request._version = matches[4];
        // 查询字符串的获取和处理
        std::vector<std::string> query_string_array;
        std::string query_string = matches[3];
        // 查询字符串的格式，先以&符号进行分割
        Util::Split(query_string, "&", &query_string_array);
        // 各个子串用等号进行分割，得到key和val，得到后需要解码
        for (auto &str : query_string_array)
        {
            size_t pos = str.find("=");
            if (pos == std::string::npos)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 400; // bad request
                return false;
            }
            std::string key = Util::UrlDecode(str.substr(0, pos), true);
            std::string val = Util::UrlDecode(str.substr(pos + 1), true);
            _request.SetParam(key, val);
        }
        return true;
    }
    bool RecvHttpLine(Buffer *buff)
    {
        if (_recv_statu != RECV_HTTP_LINE)
            return false;
        while (1)
        {
            // 1. 获取一行数据
            std::string line = buff->GetLineAndPop();
            // 2. 缓冲区的数据不足一行，获取的一行数据过大
            if (line.size() == 0)
            {
                // 判断可读长度:很长但是不足一行
                if (buff->ReadAbleSize() > MAX_LINE)
                {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414; // URI too long
                    return false;
                }
                // 不足一行但也不多，等新数据到来
                return true;
            }
            if (line.size() > MAX_LINE)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414; // URI too long
                return false;
            }
            if(line == "\n" || line == "\r\n")
                break;
            bool ret = ParseHttpLine(line);
            if (ret == false)
                return false;
        }
        // 首部处理完毕，进入头部获取阶段
        _recv_statu = RECV_HTTP_HEAD;
        return true;
    }
    bool ParseHttpHead(std::string &line)
    {
        // key: val\r\nkey: val\r\n....
        if (line.back() == '\n')
            line.pop_back(); // 末尾是换行则去掉换行字符
        if (line.back() == '\r')
            line.pop_back(); // 末尾是回车则去掉回车字符
        size_t pos = line.find(": ");
        if (pos == std::string::npos)
        {
            _recv_statu = RECV_HTTP_ERROR;
            _resp_statu = 400; // URI too long
            return false;
        }
        std::string key = line.substr(0, pos);
        std::string val = line.substr(pos + 2);
        _request.SetHeader(key, val);
        return true;
    }
    bool RevHttpHead(Buffer *buff)
    {
        if (_recv_statu != RECV_HTTP_HEAD)
            return false;
        // 一行一行数据进行获取，直到遇到空行为止
        while (1)
        {
            // 1. 获取一行数据
            std::string line = buff->GetLineAndPop();
            // 2. 缓冲区的数据不足一行，获取的一行数据过大
            if (line.size() == 0)
            {
                // 判断可读长度:很长但是不足一行
                if (buff->ReadAbleSize() > MAX_LINE)
                {
                    _recv_statu = RECV_HTTP_ERROR;
                    _resp_statu = 414; // URI too long
                    return false;
                }
                // 不足一行但也不多，等新数据到来
                return true;
            }
            if (line.size() > MAX_LINE)
            {
                _recv_statu = RECV_HTTP_ERROR;
                _resp_statu = 414; // URI too long
                return false;
            }
            if (line == "\n" || line == "\r\n")
                break;
            bool ret = ParseHttpHead(line);
            if (ret == false)
                return false;
        }
        // 头部处理完毕，进入正文处理阶段
        _recv_statu = RECV_HTTP_BODY;
        return true;
    }
    bool RecvHttpBody(Buffer *buff)
    {
        if (_recv_statu == RECV_HTTP_BODY)
            return false;
        // 1.获取正文长度
        size_t content_length = _request.ContentLength();
        if (content_length == 0)
        {
            // 没有正文，请求解析完毕
            _recv_statu = RECV_HTTP_OVER;
            return true;
        }
        // 2.当前已经接收的正文
        size_t real_len = content_length - _request._body.size();
        // 3.接收正文放到body中，但也要考虑当前缓冲区中的数据，是否是全部的正文
        // 3.1 缓冲区的数据，包含了当前请求的所有正文，则取出
        if (buff->ReadAbleSize() >= real_len)
        {
            _request._body.append(buff->ReadPosition(), real_len);
            buff->MoveReadOffset(real_len);
            _recv_statu = RECV_HTTP_OVER;
            return true;
        }
        // 3.2 缓冲区的数据，无法满足当前正文的需要
        _request._body.append(buff->ReadPosition(), buff->ReadAbleSize());
        buff->MoveReadOffset(buff->ReadAbleSize());
        return true;
    }

public:
    HttpContext() : _resp_statu(200), _recv_statu(RECV_HTTP_LINE)
    {
    }
    int RespStatu()
    {
        return _resp_statu;
    }
    HttpRecvStatu RecvStatu()
    {
        return _recv_statu;
    }
    void ReSet()
    {
        _recv_statu = RECV_HTTP_LINE;
        _resp_statu = 200;
        _request.ReSet();
    }
    HttpRequest &Request() { return _request; }
    // 接收并解析http请求
    void RecvHttpRequest(Buffer *buff)
    {
        // 不break，处理完行请求后，应该立即处理头部，而不是退出
        switch (_recv_statu)
        {
        case RECV_HTTP_LINE:
            RecvHttpLine(buff);
        case RECV_HTTP_HEAD:
            RevHttpHead(buff);
        case RECV_HTTP_BODY:
            RecvHttpBody(buff);
        }
        return;
    }
};

class HttpServer
{
private:
    using Handler = std::function<void(const HttpRequest &, HttpResponse *)>;
    using Handlers = std::vector<std::pair<std::regex, Handler>>;
    Handlers _get_route;
    Handlers _post_route;
    Handlers _put_route;
    Handlers _delete_route;
    std::string _basedir; // 静态资源根目录
    TcpServer _server;
private:
    void ErrorHandler(const HttpRequest &req, HttpResponse *rsp)
    {
        // 组织一个错误展示页面
        std::string body;
        body += "<html>";
        body += "<head>";
        body += "<meta http-equiv='Content-Type' content='text/html;charset=utf-8'>";
        body += "</head>";
        body += "<body>";
        body += "<h1>";
        body += std::to_string(rsp->Statu());
        body += " ";
        body += Util::StatusDesc(rsp->Statu());
        body += "</h1>";
        body += "</body>";
        body += "</html>";
        // 将页面数据当做响应正文，放入rsp中
        rsp->SetContent(body, "text/html");
    }
    // 将HttpResponse中的要素按照http协议格式进行组织，发送
    void WriteResponse(const PtrConnection &conn, const HttpRequest &req, HttpResponse &rsp)
    {
        // 先完善头部字段
        if (req.Close())
        {
            LOG(DEBUG, "connection is close");
            rsp.SetHeader("connection", "close");
        }
        else
        {
            LOG(DEBUG, "connection is keep-alive");
            rsp.SetHeader("connection", "keep-alive");
        }
        if (!rsp._body.empty() && !rsp.HasHeader("Content-Length"))
        {
            rsp.SetHeader("Content-Length", std::to_string(rsp._body.size()));
        }
        if (!rsp._body.empty() && !rsp.HasHeader("Content-Type"))
        {
            rsp.SetHeader("Content-Type", "application/octet-stream");
        }
        if (rsp._redirect_flag)
        {
            rsp.SetHeader("Location", rsp._redirect_url);
        }
        // 将rsp中的要素按照http协议格式进行组织
        std::stringstream rsp_str;
        // rsp_str += req._version + " " + std::to_string(rsp->Statu()) + " " + Util::StatusDesc(rsp->Statu()) + "\r\n";
        rsp_str << req._version << " " << std::to_string(rsp.Statu()) << " " << Util::StatusDesc(rsp.Statu()) << "\r\n";
        for (auto &head : rsp._headers)
        {
            rsp_str << head.first << ": " << head.second << "\r\n";
        }
        rsp_str << "\r\n";
        rsp_str << rsp._body;
        // 发送数据
        conn->Send(rsp_str.str().c_str(), rsp_str.str().size());
    }
    bool IsFileHandler(const HttpRequest &req)
    {
        // 必须设置了静态资源根目录
        if (_basedir.empty())
            return false;
        // 请求方法必须是GET、HEAD方法
        if (req._method != "get" && req._method != "head")
            return false;
        // 请求的资源路径必须是合法路径
        if (Util::VaildPath(req._path) == false)
            return false;
        // 请求的资源必须存在
        std::string req_string = _basedir + req._path; // 为了避免直接修改请求的资源路径。因此定义一个临时对象
        if (req._path.back() == '/')
            req_string += "index.html";
        if (Util::IsRegular(req_string) == false)
            return false;
        return true;
    }
    //  静态资源的请求处理
    void FileHandler(const HttpRequest &req, HttpResponse *rsp)
    {
        std::string req_string = _basedir + req._path;
        if (req._path.back() == '/')
            req_string += "index.html";
        bool ret = Util::RealFile(req_string, &(rsp->_body));
        if (ret == false)
            return;
        std::string mime = Util::ExtMime(req_string);
        rsp->SetHeader("Content-Type", mime);
    }
    // 功能性请求的分类处理
    void Dispatcher(HttpRequest &req, HttpResponse *rsp, Handlers &handlers)
    {
        // 在对应请求方法的路由表中，查找是否含有对应资源请求的处理函数，有则调用 ，没有则返回404
        for (auto &e : handlers)
        {
            const std::regex &re = e.first;
            const Handler &functor = e.second;
            bool ret = std::regex_match(req._path, req._matches, re);
            if (ret == false)
                continue;
            return functor(req, rsp); // 传入请求信息，和空的rsp，执行处理函数
        }
        rsp->_statu = 404;
    }
    void Route(HttpRequest &req, HttpResponse *rsp)
    {
        // 对请求进行分辨，是一个静态资源请求，还是一个功能性请求
        // GET HEAD都默认先认为是静态资源请求
        if (IsFileHandler(req))
            return FileHandler(req, rsp);
        if (req._method == "GET" || req._method == "HEAD")
            return Dispatcher(req, rsp, _get_route);
        else if (req._method == "POST")
            return Dispatcher(req, rsp, _post_route);
        else if (req._method == "PUT")
            return Dispatcher(req, rsp, _put_route);
        else if (req._method == "DELETE")
            return Dispatcher(req, rsp, _delete_route);
        rsp->_statu = 405; // method not allowed
    }
    // 设置上下文
    void OnConnected(const PtrConnection &conn)
    {
        conn->SetContext(HttpContext());
        LOG(DEBUG, "new connection %p", conn.get());
    }
    // 缓冲区数据解析和处理

    void OnMessage(const PtrConnection &conn, Buffer *buffer)
    {
        while (buffer->ReadAbleSize() > 0)
        {
            // 获取上下文
            HttpContext *context = conn->GetContext(buffer)->get<HttpContext>();
            // 通过上下文对缓冲区数据进行解析，得到HttpRequest对象
            // 1.若缓冲区的数据解析出错，就直接回复出错相应
            // 2.若解析正常，且请求已经获取完毕，才开始处理
            context->RecvHttpRequest(buffer);
            HttpRequest &req = context->Request();
            HttpResponse rsp(context->RespStatu());

            if (context->RespStatu() >= 400)
            {
                // 进行错误响应，关闭连接
                ErrorHandler(req, &rsp);
                WriteResponse(conn, req, rsp);
                context->ReSet();
                buffer->MoveReadOffset(buffer->ReadAbleSize());
                conn->Shutdown(); // 关闭连接
                return;
            }
            if (context->RecvStatu() != RECV_HTTP_OVER)
                return; // 当前请求没有接收完整则退出，等新数据到来再重新继续处理
            // 请求路由 + 业务处理
            Route(req, &rsp);
            // 对HttpResponse进行组织发送
            WriteResponse(conn, req, rsp);
            // 重置上下文
            context->ReSet();
            // 根据长短连接判断是否关闭连接或者继续处理
            if (rsp.Close() == true)
                conn->Shutdown(); // 短连接关闭
        }
    }
public:
    HttpServer(int port, int timeout = DEFAULT_TIMEOUT) : _server(port)
    {
        _server.EnableInactiveRelease(timeout);
        _server.SetConnectedCallBack(std::bind(&HttpServer::OnConnected, this, std::placeholders::_1));
        _server.SetMessageCallBack(std::bind(&HttpServer::OnMessage, this, std::placeholders::_1, std::placeholders::_2));
    }
    void SetBaseDir(const std::string &path)
    {
        bool ret = Util::IsDirectory(path);
        assert(ret == true);
        _basedir = path;
    }
    // 设置或添加请求(请求的正则表达式)与处理函数的映射关系
    void Get(const std::string &pattern, const Handler &handler)
    {
        _get_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Post(const std::string &pattern, const Handler &handler)
    {
        _put_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Delete(const std::string &pattern, const Handler &handler)
    {
        _delete_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void Put(const std::string &pattern, const Handler &handler)
    {
        _put_route.push_back(std::make_pair(std::regex(pattern), handler));
    }
    void SetThreadCount(int count)
    {
        _server.SetThreadCount(count);
    }
    void Listen()
    {
        _server.Start();
    }
};